'Polar Vortex' hits the Midwest

Workers brave sub-zero temperatures to clear snow from the steps of Ellsworth Hall on the University of Kansas campus in Lawrence, Kan., Monday, Jan. 6, 2014. The area is under a wind chill warning until noon Monday. (AP Photo/Orlin Wagner)

Two pedestrians go down a street in Chicago's South Loop with temperatures well below zero and wind chills expected to reach 40 to 50 below Monday, Jan. 6, 2014, in Chicago. A whirlpool of frigid, dense air known as a "polar vortex" descended Monday into much of the U.S. (AP Photo/Charles Rex Arbogast)

Fred Osterwisch uses a snowblower to clear the walk way in front of this house in Ann Arbor during Sundays snow storm, Jan. 5, 2014. Michigan residents have been preparing for the harshest winter conditions in 20 years, with a foot of snow already on the ground by Sunday evening. (AP Photo/The Ann Arbor News, Courtney Sacco) LOCAL TV OUT; LOCAL INTERNET OUT

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Lee Tuttle, 66, takes a break from blowing snow off of his driveway to pose for a portrait on Sunday, January 5, 2014 at his home on Miller Road in Flint, Mich. He said he hadn't really noticed the icicles forming in his beard. (AP Photo/The Flint Journal, :Michelle Tessier) LOCAL TV OUT; LOCAL INTERNET OUT

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Jack Leonard, 11, left, and Cedric Berrouet, 11, right, were among the crowd of sledders who took advantage of Sunday's warmer temperatures and hit the hill at Citizens Park in Sunday Jan. 5, 2014, in Ridgewood, NJ. (AP Photo/The Record, Amy Newman)

Dave Dull cross country skis along State Street to his office Sunday, Jan. 5, 2014, on the campus of Purdue University in West Lafayette, Ind. Dull said he wanted to get out for a little fresh air and some exercise. The National Weather Service issued a winter storm warning until late Sunday for central Indiana (AP Photo/Journal & Courier, John Terhune)

Rick Gibson shovels the snow from his neighbor's driveway on West Kalong Circle in Southfield, Michigan on Sunday, Jan. 5, 2014, as metro Detroit digs out from a severe winter snow storm. (AP Photo/ The Detroit News, David Guralnick)

CORRECTS MEMBER NAME and ADDS RESTRICTIONS- With temperatures at about 22 below zero with a -50 windchill, it was hard to find the beauty in the brutal weather in Bismarck, N.D., Sunday, Jan. 5, 2014. Sundogs, a ring of light visible around the sun or moon when light is refracted through ice crystals in the atmosphere, are quite beautiful along Highway 83 north of Bismark ND. (AP Photo/The Star Tribune, Brian Peterson) MANDATORY CREDIT; ST. PAUL PIONEER PRESS OUT; MAGS OUT; TWIN CITIES TV OUT MBO

Three brothers, from left, Trevor, Connor, and Austin Bartz built this 16 foot high snow shark in the front yard of their New Brighton, Minn. home, Wednesday, Jan. 1, 2014. It took them around 95 hours of work and they gathered the snow from houses in their neighborhood. (AP Photo/Star Tribune, Glen Stubbe) ST. PAUL PIONEER PRESS OUT, MINNEAPOLIS-AREA TV OUT, MAGS OUT

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Jenny Hackett walks across a street in St. Louis as snow and wind swirls around Sunday, Jan. 5, 2014.. Heavy snow continues to fall Sunday with forecasters calling for up to a foot (30 centimeters) in eastern Missouri and parts of central Illinois followed by bitter cold. (AP Photo/Jeff Roberson)

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Anna Maksimkina of Yekaterinburg, Russia, sleeps on the floor at Kennedy International Airport after a Delta flight from Toronto to New York skidded off the runway into a snow bank, temporarily halting all flights, Sunday, Jan. 5, 2014, in New York. Authorities have said to to expect delays and flight cancellations because of the cold temperatures. (AP Photo/Kathy Willens)

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A semi-truck move slowly through blowing and falling snow as a strong winter storm passes through the Midwest Sunday, Jan. 5, 2014, in Springfield, Ill. Temperatures not seen in years are likely to set records in the coming days across the Midwest, Northeast and South, creating dangerous travel conditions and prompting church and school closures. (AP Photo/Seth Perlman)

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A crew works to de-ice planes at O'Hare International Airport in Chicago on Sunday, Jan. 5, 2014. In Chicago, temperatures were expected to fall throughout Sunday to about 11 degrees by 5 p.m. About 1,200 flights had been cancelled Sunday morning at O'Hare and Midway international airports in Chicago, aviation officials said. (AP Photo/Nam Y. Huh)

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A person struggles to cross a street in blowing and falling snow as the Gateway Arch appears in the distance Sunday, Jan. 5, 2014, in St. Louis. Snow that began in parts of Missouri Saturday night picked up intensity after dawn Sunday with several inches of snow on the ground by midmorning and more on the way. (AP Photo/Jeff Roberson)